Production of dense, defect-free and uniform nanopatterns over a large area is of significant concern for the semiconductor fabrication industry. State-of-the-art fabrication techniques include photolithography (immersion optical and interference lithography) and scanning electron-beam lithography (SEBL). However these techniques are limited by factors such as low throughput due to the serial patterning nature of SEBL or lower inherent resolutions limits of optical lithography, which require solutions to challenging physics problems such as finding appropriate low wavelength light sources (EUV) and material systems that can properly act as resists for such light sources. Developing technology to overcome such limitations is of significant concern for the semiconductor fabrication industry in shrinking the size of transistors for integrated circuits.
A promising solution to overcoming such limitations is the directed self-assembly (DSA) of block copolymers (BCPs) through physical templating. BCPs are composed of chemically distinct polymer chains (blocks) that are covalently bonded at their ends. When a thin film coating of BCPs is annealed, the polymer self-assembles to form nano-scale structures due to microphase separation, often with dimensions in the range of 5 nm to 100 nm. The pattern templates made with BCPs can be used as a mask for further pattern transfer into functional materials such as insulating, semiconducting, and conducting materials.